<script setup lang="ts">
import { ref } from 'vue';
const isActive = ref(false)
</script>


<template>
  <div id="app">
    <div class="box1" :class="{ box2: isActive }"></div>
  </div>
</template>

<style>
.box1 {
  width: 200px;
  height: 200px;
  background-color: red;
}

.box2 {
  border-radius: 50%;
}
</style>
